I’m not sure the thread has run its course, and besides, it’s a rant, not a technical topic… That said, let’s get technical.
First, lane detection is done by cameras/color sensors, not GPS. ArduPilot can be fed obstacle data from similar systems should you want to invest in them.
Second, automotive GPS is no better than anything we have access to install on our vehicles. If the system in your car seems more accurate, that’s because it either leverages your cell phone to increase accuracy via cell tower/wifi positioning and/or uses AI to assume that it’s on the nearest road and traveling in the general direction of your GPS track. Have you ever watched your car’s symbol travel down an exit you haven’t taken or continue down a highway when you’re on an access road? That’s the navigation software making assumptions regarding its position that in most cases results in a perceived high level of accuracy but sometimes fails.
A uBlox F9P or even M8P module almost certainly has more native capabilities than any given automotive GPS in its raw form. ArduPilot’s navigation system is nothing short of impressive on many flight controllers, going from boot to a fully aligned INS with GPS correction in a matter of seconds or maybe a minute or two, which is easily faster (and, with RTK, more accurate) than commercial or even military aircraft GPS/INS alignments (4-9 minutes, typically, sometimes requiring manual starting coordinate entry and/or manual GPS almanac updates).
Rant and rave all you want, but I don’t want to use an automotive navigation system with all of its assumptions and limitations for a mower in a field or a copter doing aerial photography/survey…or…well, just about anything other than a road-going car.